// win32.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "resource.h"

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;								// current instance
TCHAR szTitle[MAX_LOADSTRING];								// The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];								// The title bar text

																	// Foward declarations of functions included in this code module:
ATOM				MyRegisterClass(HINSTANCE hInstance);
BOOL				InitInstance(HINSTANCE, int);
LRESULT CALLBACK	WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK	About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,//当前实例句柄
	HINSTANCE hPrevInstance,//NULL,为了兼容
	LPSTR     lpCmdLine,//该字符串包含传递给应用程序的命令参数
	int       nCmdShow)//指定程序的窗口应该如何显示
{
	// TODO: Place code here.
	MSG msg;
	HACCEL hAccelTable;

	// Initialize global strings
	LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);//将szTitle赋值为字符串IDS_APP_TITLE
	LoadString(hInstance, IDC_WINDOWSPROJECT1, szWindowClass, MAX_LOADSTRING);//将szWindowClass赋值为字符串IDC_WINDOWSPROJECT1
	MyRegisterClass(hInstance);

	// Perform application initialization:
	if (!InitInstance(hInstance, nCmdShow))
	{
		return FALSE;
	}

	hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_WINDOWSPROJECT1);

	// Main message loop:
	while (GetMessage(&msg, NULL, 0, 0))	//编写消息循环码
	{
		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
		{
			TranslateMessage(&msg);//请求Windows为那些与键盘有关的消息做一些特殊转换工作
			DispatchMessage(&msg);//请求Windows分派消息到窗口过程，由窗口过程函数对消息进行处理
		}
	}

	return msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)//设计窗口类
{
	WNDCLASSEX wcex;//创建WNDCLASSEX类型的对象

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style = CS_HREDRAW | CS_VREDRAW;							//设置窗口的样式
	wcex.lpfnWndProc = (WNDPROC)WndProc;							//回调函数
	wcex.cbClsExtra = 0;											//可以请求额外空间
	wcex.cbWndExtra = 0;
	wcex.hInstance = hInstance;										//指定当前应用程序的实例句柄
	wcex.hIcon = LoadIcon(hInstance, (LPCTSTR)IDI_WINDOWSPROJECT1); //指定窗口类的图标句柄
	wcex.hCursor = LoadCursor(NULL, IDC_ARROW);//指定窗口类的光标句柄
	wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);//指定窗口类的背景画刷句柄
	wcex.lpszMenuName = (LPCWSTR)IDC_WINDOWSPROJECT1;//lpszMenuName是一个以空终止的字符串
													 //如果该窗口没有菜单，则应该将其设为0
	wcex.lpszClassName = szWindowClass;//指定窗口类的名字
	wcex.hIconSm = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL);//标识某个窗口最小化是显示的图标

	return RegisterClassEx(&wcex);//调用RegisterClassEx()函数向系统注册窗口类
}

//
//   FUNCTION: InitInstance(HANDLE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
	HWND hWnd;

	hInst = hInstance; // Store instance handle in our global variable
					   //创建窗口
	hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
		CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

	if (!hWnd)
	{
		return FALSE;
	}

	ShowWindow(hWnd, nCmdShow);//初始化窗口
	UpdateWindow(hWnd);//通知Windows应用程序重绘客户区

	return TRUE;
}

//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND	- process the application menu
//  WM_PAINT	- Paint the main window
//  WM_DESTROY	- post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)//窗口过程函数
{
	int wmId, wmEvent;
	PAINTSTRUCT ps;
	HDC hdc;
	TCHAR szHello[MAX_LOADSTRING] = L"Hello World";
	LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);

	switch (message)
	{
	case WM_COMMAND:
		wmId = LOWORD(wParam);
		wmEvent = HIWORD(wParam);
		// Parse the menu selections:
		switch (wmId)
		{
		case IDM_ABOUT:
			DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
			break;
		case IDM_EXIT:
			DestroyWindow(hWnd);
			break;
		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
		}
		break;
	case WM_PAINT:
		hdc = BeginPaint(hWnd, &ps);
		// TODO: Add any drawing code here...
		RECT rt;
		GetClientRect(hWnd, &rt);
		DrawText(hdc, szHello, _tcsclen(szHello), &rt, DT_CENTER);
		EndPaint(hWnd, &ps);
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hWnd, message, wParam, lParam);
	}
	return 0;
}

// Mesage handler for about box.
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	switch (message)
	{
	case WM_INITDIALOG:
		return TRUE;

	case WM_COMMAND:
		if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
		{
			EndDialog(hDlg, LOWORD(wParam));
			return TRUE;
		}
		break;
	}
	return FALSE;
}
